Use implicit instead of explicit defaulted constructor for SendDataParams

The explicitly defined constructor suppresses the assignment operator,
which blocks the chromium roll.

Bug: b/198565646
Change-Id: I35917d4b99ad86dcf8b9863e798f5a63d9073824
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/231123
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#34904}

api/transport/data_channel_transport_interface.h

diff --git a/api/transport/data_channel_transport_interface.h b/api/transport/data_channel_transport_interface.h
index 52c8522..cdae6fe 100644
--- a/api/transport/data_channel_transport_interface.h
+++ b/api/transport/data_channel_transport_interface.h
@@ -35,9 +35,6 @@
 // sent reliably and in-order, even if the data channel is configured for
 // unreliable delivery.
 struct SendDataParams {
-  SendDataParams() = default;
-  SendDataParams(const SendDataParams&) = default;
-
   DataMessageType type = DataMessageType::kText;
 
   // Whether to deliver the message in order with respect to other ordered